If you are trying to send a file to a windows shortcut or network drive then the Scan to Folder feature will not work. You must use the Fully Qualified URL when attempting to Scan to Folder.
Scanning to something like \\192.168.1.1\c$\users\userID\desktop is not going to work because C$ is a windows shortcut for the C:\ drive. The same problem would happen if you tried to scan to a network drive letter since drive letters are also windows shortcuts. For example L:\desktop is invalid, but \\192.168.1.1\myDesktop can be valid if that directory is shared out correctly.
For network scanning I suggest using an IP Address instead of a computer name as the default location. Inserting computernames forces the printer to rely on a different feature called WINS that can cause issues. If its safe to share your URL then try posting it for us to review.